DoubbleB - Which B10 do you have? is it a 3.2? 3.3? 4.6? or a 4.8? - they are nice cars, I (bro and sis in law) had an E46 B3S convertible - nice car but for me, it didn't quite hit the mark overall, I'd have preferred an M3.
A friend of mine has a very rare E39 B10 V8S Touring which I went with him to the Nurburgring in did a couple of laps and then drove back all over a weekend! Again, a fantastic car, fast as well - but for me the M5 is the one to go for. The Alpina is absolutely fantastic for keeping a very low profile as not many non enthusiasts know what one is - they look quite plain overall with just the wheels being the main visual give away.
There are a 'few' Alpina's and other interesting BMW's which have been federalized and taken to the USA, and I daresay most of them do end up being garage Queens due to rarity etc. Over here, they're still rare but can be had quite cheaply now as our fuel is so expensive and there's much less of a market looking for a big engine, very expensive to maintain car. Currently a rare 2002 B10 V8S is up for sale at just £8K which is around $12500 USD and has been so for a couple weeks now at least.
G Moussa - Another very good friend I often see at meets and shows has a 540i and has done some very high end modifications in order to make it an Alpina-like. Powered trunklid conversion, genuine Alpina wheels, suspension and bumpers and exhaust. Another UK forum member has done very much the same but on an E39 Touring as well!