Unfortunately there aren't any really good affordable options. As far as I know, the Winter altimeters are not TSO'd (at least the 2" ones), though I think you can get an EASA form 1 with them. Also, the 2" versions from United or Mid-Continent are around $4K, the 3" ones over $1K. If you get to the $4K range, honestly you're probably just as well off to get one of the lower priced certified Aspen Avionics units instead of the analog Altimeter (the reliability will be better, and you get a full fledged EFIS along with it).
In the end the 3" units will cost much less than the 2" units (by a huge margin). I also assume you'll need one in Millibars instead of Inches...which again can somewhat limit your options.
Sorry to be the bearer of bad news, but we've seen this many times with various countries that require the altimeter or other parts to be TSO'd.
Cheers,
Stein