Spring Time

Car went into Audi for a service yesterday and unfortunately on the health check, they've picked up a NSR spring broken

Obviously Audi want an extortionate amount of money to fix it with the spring alone being £122 inc. VAT plus labour so total bill of £296. I've been looking around the Interweb and I can pick up a Bilstein OEM replacement for £55 or £76 for two which matches my spring weight code but alternatively I've seen the Eibach Pro Kit for £138.00.

It's an SE Avant - sometimes it feels a little bit spongy which is expected with SE suspension but I have 19" wheels so the ride can be a little bit harsh on country roads. If I go for an Eibach kit, will the ride degrade much? Also, what kind of price am I looking for an indie (on average) to fit as all 4 corners will need doing. Is it doable myself or is it a pig of job? I've currently got no spring compressors so will have to buy tools as well to add to the cost if I do myself but I do my own brakes so not too un-handy in that department.

The other alternative is to look for a whole set of S-Line/Sport suspension off Fleabay but not sure about ending up with a load of knackered parts

If just going for an Audi/Bilstein OEM spring, is that doable myself? Also, should I replace in pairs?

When the other half had her C6, we had a rear spring go on that too just as we were in the process of trading it in so ended up having a KYB on that one.

I've had a look at the Audi guide and it shows you needing the VAS tool which fits from the underneath to compress the springs. My main concern about doing it myself is being able to compress the spring to get it out and back in again - also how much needs to be taken apart to get the hub low enough.