WestyOwnerI've had a Philishave 850 3-head one for about 30 years I think

It's had several new cutter sets, and a couple of new batterys from
www.shavers.co.uk and is easily the best shaver I've ever had.
I was at the same point as you about 3 or 4 years ago and thought I'd splash out and get the latest Philips one to replace it, which at that time was
this one although i'm sure it wasnt that much then.
A bit disappointed with it really, and still use the old 850 from time to time. the new one seems to need emptying every day and seems to need more passes than the old 850 to have a proper shave, so take longer. therefore my advice would be get some spares for the old one and refurbish that.
Bernie