I appreciate financial decisions are difficult when it is 'only' a hobby, but some common sense needs to be applied. Under £900 for a new Quintet Black less the trade-in value may be twice as much as a retip (I don't know the exact figures), but in effect, the actual monetary difference is therefore £300.
So, for £300 extra, you get a brand new catridge (including, of course, suspension, etc.) that is as the manufacturer and designer intended. Or for £300 less, you can have a cartridge with its original, old, suspension and a stylus that is different. To me, that's a no-brainer. In the overall scheme of things, £300 does not seem an excessive difference for total peace of mind.
Alternatively, it's an excellent opportunity to look at (listen to) alternative cartridges entirely.