I find the sellers modelsforsaleltd and flagbearer101 on the 'Bay to be pretty reasonable.
I do find two issues with plastics though. One is that there are usually a lot of redundant figures you can't use.
The worst example of this must be the Airfix French infantry. I look at these now and I wonder that I ever persisted with Napoleonics from a start like these. You nominally get 45 "pieces" per set. Three of these "pieces" are the officer and his horse, however, so that leaves 42 potential combatants. Among these 42 are two dead men and one carrying a wounded comrade, which takes you down to 39 usable combatant figures. Six of these are loading figures so sculpted that they occupy more width than any other figure, or even a 28mm metal figure, and won't fit into my standard frontage. So from 45, we're already down to 33.
Of these, there are four figures who appear inexplicably to be hopping on one leg while listening to the barrel of their muskets, and are too daft to use; which leaves 29. Two of these 29 appear to be squatting almost on their heels and wielding their muskets like guitar heroes, which is also silly and leaves 27. One of these is an eagle bearer who has a flag, but no eagle, who is dressed exactly the same as everyone else, even though he is an officer. Of the 26 left, one's a bugler. Buglers are spurious – in line units at least.
Of the 25 remaining figures, one's a drummer, 11 are standing firing or kneeling firing, six are marching (with musket on the wrong shoulder for rank-and-file), four appear to be parrying with their bayonet, and the other three are kneeling on guard. All these are usable.
Thus in a French box of 45 "pieces", only 25 of them – 56% – are usable, largely down to gratuitous pose variation. But it actually wasn't even as good as that, because these 25 usable figures didn't then assemble conveniently into units composed the way I wanted them. An 18-figure, six-company battalion needed three standing firing for the grenadier company, three kneeling firing for the voltigeur company, one to three command figures, and thus between nine and eleven further figures, in a single stance, for the fusilier companies. There aren't eleven such figures in a set, nor even nine – so to make just one tidy-looking battalion requires more than one set.
Even today, if you want 95th Rifles, the Italeri are lovely but unless you're doing skirmish, few people are going to need 48 of them. Likewise the HaT Grenadiers a Cheval, where 12 aren't enough but 24 are too many unless you are using generous unit sizes (although you can use the spares as elite company dragoons).
The other thing is this "pieces" malarkey, which is irritating generally. HaT 8297, their Napoleonic French Command set, looks stonking value at £7.99 GBP for 92 pieces from flagbearer101 including delivery. 92 pieces! Ooo! 92 blokes! Er, no. This is four identical sprues of 24 "pieces" each, with five foot figures and one mounted officer apiece. So twenty blokes and four officers, not 92.
I guess you just bag up your spares and flog them on the 'bay as spares.