Went in to look at double prams today (expecting our second in a couple of months), and the store rep advised of a big sale coming up. She said the sale is store wide but excludes best-buy items (so, not store wide- I hate it when they do this) which are effectively baby bunting's version of "every day low priced" items. They are releasing a catalogue in a couple of days with all the sales and hopefully the exclusions- I assume exclusions apply, so I will update the post once baby bunting advertises the sale. If you're looking at buying a big ticket item, i.e. a pram, stroller, carrier, capsule, change table, cot, etc. I'd say it's definitely worth waiting for the sale.
For prams, car seats, capsules etc the 20% off will be off RRP, which none of the stores ever sell at anyway.
Car seats are on permanent "everyday low price" so you have to hunt for special sales where they include them at a lower than normal "low" price.