How does your company scale salary/benefits for part-time work?

Context:

We're a small startup in the UK trying to figure out our hiring policies. An idea we've tossed around before is that since we offer remote work with fairly flexible hours, there's a terrific opportunity to hire people who are taking a career break due to their personal life (young children etc).

Our perceived benefit is:

* we're getting access to a talent pool that might otherwise be ignored

* the offerings that are very possible as a small company (remote, flexible hours, easy access to management) are far more impactful to someone in this situation

* we have a future opportunity to let our bandwidth grow

The cost of two part-time employees isn't quite the same as one full-time, since we incur about the same fixed costs anyway (management time in 1-2-1's, payroll administration, dev setup etc). So we're wondering if cutting the salary in half is actually what we want to do?