has anyone re-upholstered their sofa/armchairs before?

[fez]

how much does it cost to get this professionally done? thinking of re-upholstering an arm chair but not sure if it is worth it...

Had a couple of chairs done professionally and it costed a couple of hundred for each. I don't think either chair is so valuable in itself, but it was worth it for me and the job was done really well. If you can strip it down yourself, that will save a bit of money.

Have you picked out a fabric, do you know how much of it you'll need, and what it costs? That can be as much, if not more than the cost of having the re-upholstering done....

It depends,

on type of chair (button backs are more expensive for instance as this is time consuming)
type of fabric you use
fabric has to be fireproof and also so do the cushions - this is expensive. Cushions about £12 each now so 4 would be about £50 alone.
Usually get a quote for the job rather than hourly rate.

Evening classes?

oh dear. sounds more effort than it is worth. may just buy a cheap one from ikea then. it's just that we have an old one from habitat which is still structurally sound but the fabric is looking quite old from the countless washes (it was in ds1 and now ds2 room all through the feeding days!). having watched countless home improvements programme thought if it wasn't that expensive, it might be nice to have a really colourful and fun one. no earlybird. haven't seen a fabric. to be honest, don't know where to start really.