DD (2yo) is getting:
Bubbles - 50p from Tiger
Large choc coin - £2 Boots (but "free" on points)
Happyland surprise figure £1.60
Satsuma
Apple
Red flock bouncy ball £3
CBeebies magazine (free as we got sent a few free earlier in the year - long story - and I put this one aside for the stocking as it has a nice plastic ninky nonk with it)
Hair slides and bobbles - £3.50
Ikea soft toy mouse - £1
Munchkin bath bugs (on points in the Boots summer sale, reduced to £2 anyway)
Light-up bath ducks from Tiger - £3 I think?
Paper animals from Tiger - £1
Hotel Chocolat Tiddly Pot (mini choc buttons) - can't remember price, about £3 I think
Pretty much everything was in the sale and/or under a couple of pounds/under £2 anyway/free/on Boots advantage card points - I estimate I spent nearly exactly £20 in total on the stocking, which I think isn't too extravagant? Around £20 for the stocking seems to me about right for a 2yo - certainly not necessary to spend more and I probably could have spent less!
My parents did a stocking of fun bits but not tat - little wooden puzzles, kaleidoscopes, gyroscope, stuff from the John Lewis pocket money section type toys type of thing; then we'd have a main FC present under the tree and a few other bits and pieces from mummy and daddy. I plan to do the same kind of thing. I loved my stocking presents - they were possibly the best bit of Christmas for me and I still remember some of them fondly nearly 30 years later :)
The rest of DD's presents:
Munchkin bath tug boat set, bought with Boots points in the summer sale - £5 (in points so kind of free) - Father Christmas might possibly give this I think.
From us:
--Toy jogger buggy from John Lewis - £20 (bought with high street shopping vouchers from my saved up E-on energy points);
--Brio coffee set - I saw this reduced to £7.99 in a sale and thought it was so hipster! DH will like it as he's an espresso fiend and always bemoans that DD only makes pretend tea not pretend coffee ;)
--Sarah & Duck DVD (£5 from Amazon), plus mini plush Sarah & Ducks (got when the price reduced to around £9 with postage on Amazon), plus Sarah & Duck meet the penguins book (£5) (can you tell what DD's favourite programme is yet? ;) ) - Sarah & Duck bundle total £19
--Plus some bath boats from Ikea, £3
= so around £50 from Mummy and Daddy. As a "big" present, Father Christmas will bring a faux-Brio-style (but cheaper!) train set from Tesco (on Clubcard points). All in all, I estimate we'll probably spend the equivalent of around 100-120 pounds including the stocking, though some of that will be funded by saved Boots and energy points and clubcard points and so on. I have the sense that we're kind of in the middle with presents - well, I like to think, not too few and not too many - though I know my sister spends a lot more each on her children, probably more like £300-400 per child, which seems a lot to me for preschoolers! 
I tend to buy throughout the year at places like Ikea and Tiger, especially for stocking things, and stash away, so that it spreads the cost. I'm aware that this is more than lots of children get, but also far less than others (DD has no concept of iPads or tablets and I hope to keep it that way as long as possible for the sake of my bank balance! :))