"How much?" was the response I got when I admitted what my new Leica M-E camera set me back. Since then I've tried to dodge the question – "Oh look, a hoopoe bird"; "Anyone for coffee?" – or fudge it: "Well, I sold a lot of kit and used a tax rebate which paid off most of it." But I've been gulping at the possible foolishness of such a big investment in a recession, and asking myself if it was really worth £3,900.



Playing devil's advocate, I must say that the M-E is not the best camera I've owned in low light (the ISO promises more, but I wouldn't be happy using it over 1250); the screen on the back is a lower resolution than the one on my phone; the buffer is achingly slow; and since Leica glass is so expensive, I could only afford one lens – a secondhand 50mm ASPH f1.4.



Yet despite all these negatives, the M-E is the most pleasurable camera I have ever used. A 50mm is a decent portrait lens, and only having one lens means the sensor is far less dusty. Although it's early days, I'm already pleased with the results – we seem to do good work together, the Leica and I. The limitations merely force me to be more thoughtful about how I shoot, and it has reignited the enthusiasm that made me want to be a professional photographer in the first place.

Leica has a reputation as the world's best lensmaker, but it's a purist brand and has taken some years to successfully marry the essentials of rangefinder photography with digital technology. The M9 was a distinct improvement on its first digital M series camera, the M8, but it was so expensive that most photographers were priced out of the market (in press photography circles it's known as the "dentist's camera"). So the M-E is a welcome attempt by Leica to open up the market to working photographers, rather than just the oligarch crowd (or dentists).

A woman and her dog near King's Cross, London. Photo: Sarah Lee for the Guardian

It's identical in build, materials, sensor, inset-software and chip to the M9, but 20% cheaper. The only significant differences are the preview lens selector lever and the USB port. Neither of these are features I would use, so their absence doesn't bother me. Of course, other people might miss them – but miss them to the tune of four figures?



In contrast to shooting portraits with a huge DSLR, my experience with the M-E has been that people aren't intimidated, they're curious. The Leica's retro-elegance makes it a subject-friendly camera, which makes my job easier.



The Leica rangefinder is world famous for street photography, and this has a lot to do with how the rangefinder changes the visual experience for the photographer. The subject can be seen even when the shutter is pressed, so there's no momentary blindness, and no loss of connection between photographer and subject.



I've only had my M-E for a month, but I'm more attached to it than I've been to any other camera I've owned since I turned professional. I still have a nostalgic fondness for the battered Pentax K1000 I had as a student, when I was trying to learn as much as I could about photography without having to spend a lot of money. Few starting out in the profession will be able to afford the Leica M-E, which is an issue. But once you can, it changes everything.

Night bus near Oxford Circus, London. Photograph: Sarah Lee for the Guardian

The Leica has reconnected me with the way I worked when I was starting out. The excitement you experience in the beginning, as you master the necessary techniques and become proficient, wears off over the years. I love working to a brief, and still get a kick from seeing my work published, but I have gradually moved away from the simple way I worked as a student, wandering around town just for the experimental pleasure of finding good compositions. I'm doing it again now, feeling that same innocent kick from making pictures rather than just fulfilling briefs. Hopefully this reinvigoration will translate into all areas of my work.



On my first weekend with the M-E, I took it to central London to get a feel for using the rangefinder and to practise focusing in a street-photography environment. I was struck by the number of people who clocked the distinctive red dot logo. One commented: "That's a nice Leica love, did your husband buy it for you?" (Grrrrrr!). Given that I was attempting to be discreet, this was unnerving. It occurred to me that some of London's more enterprising thieves may recognise the logo and make me their target. I solved the problem by covering it with gaffer tape. Since then, I haven't had any comments from passersby.

Sarah Lee with her gaffer-taped Leica. Photograph: Sarah Lee for the Guardian

The Leica feels different in the hand from other cameras in ways that are not easy to define (I find myself caressing the damn thing). The design is simple, little changed from the first Leica rangefinders of the 1940s – why mess with a good thing? My everyday Japanese DSLR is the camera equivalent of a people carrier: it does what it is supposed to do, but it is not an object of beauty. The Leica feels and looks (even in its digital form) like the equivalent of Inspector Morse's Mark II Jaguar.



The images have a rich, warm tone and a sharpness that more dedicated Leica blogs (and there are a lot of them) could describe better. I'm not sure how much is to do with the glass and how much the technology, but I can see and feel the difference. I've even started taking my images to be printed again – something I haven't done for a long while.



So the purchase of my newly beloved Leica may have ruptured my bank account. Christmas may have been put on hold. But so what? It's reconnected me with why I became a photographer in the first place. Worth it? Yes.