Oh, you've opened a whole can of worms here, this will be long!
Bought a secondhand pushchair for about £50, a mothercare one that was about 3 years old, it came with a car seat that clicked on but we bought a new car seat anyway (not trusting a secondhand one). It was really similar to this one here www.mothercare.com/Mothercare-Trenton-Deluxe-Pushchair-Travel/dp/B001SADRYM?_encoding=UTF8&
Have sold it since for £40 as we now have a double buggy, but that means that for the year we had it we only spent £10, less than a pound a month!
Ebay, Gumtree and Freecycle are your friends!
I bought the Sniglar cot from Ikea and am really happy with that too, it was only about £35, bought a mattress from babymattressesonline.co.uk for cheaper than Ikea though for about £20.
Didn't bother with moses basket/crib, just put cot next to our bed.
Breastfed so didn't need to buy formula, thankfully had no problems with bfeeding.
Use washable wipes (well, I did until my second was born and I couldn't keep up) but don't buy them, its an utter con!
Just buy cheap face flannels from wilkos or similar or buy a big fleece blanket and chop it up (this also works for fleece liners for your washable nappies, never buy them, again a total con). You can keep them damp in a tupperware box or an old ice cream tub ready to use or buy a water spray bottle and spray wipe or bum as required.
Didn't buy cot sheets, they are so expensive for what they are. I cut up, hemmed and elasticated our spare old double bed sheets to make fitted cot sheets.
Didn't buy baby towels, waited for some towels to be reduced and cut them in half to make perfect baby sized towels. They aren't as cute as special baby towels but the baby has no idea!
Found a baby sling on Freecycle, and a big set of baby toys (that I sterilised in milton before using), also got a baby gym/activity arch which I put through the washer on a hot wash (they had a cat and I'm allergic).
Don't buy a highchair, just get a booster seat. Both of mine have been fine in this www.argos.co.uk/static/Product/partNumber/3972520.htm?_$ja=tsid:11527|cc:|prd:3972520|cat:nursery+/+feeding+and+bathing+/+other+baby+accessories+/ booster seat from about 12 weeks, easily in time for weaning at 6 months. Its great because in a small house you don't lose space for a large highchair and you don't need to buy a travel highchair/booster seat because you can just take that one with you. You can get them secondhand quite cheap, here is one on ebay for buy it now £12 cgi.ebay.co.uk/Fisher-Price-Booster-Seat-used-/170589904750?pt=UK_Baby_Babay_Feeding_Highchairs_Boosters_LE&hash=item27b7f35f6e#ht_500wt_898
I only paid £15 for each of mine, I now recommend them to everyone I know.
I still get a lot from NCT sales, I've bought all sorts from there. Aim to get there right at the start, grab anything you think you might want - its ruthless in there - once you have a good stash sit at the side and look through what you have and put back anything you don't really want. Always think ahead, if you see a real bargain but you don't need it until next year still buy it (if you can), I think £3 in a charity shop now is better than £20 in mothercare next year.
When you wean, always make your own for the baby, its healthier and cheaper than buying all those jars of food (provided you have a freezer).
Can probably think of more but think that might be enough.
The hardest thing is going into Mothercare and seeing all the beautiful things and wanting them but being sensible and getting things cheaper elsewhere. I can honestly say though that it doesn't bother me now and my DDs are none the wiser. TBH we're better off now but once you get into the habit of being frugal its hard to give up!