Yes these MPU boxes make me sick 🤐
I even contacted a few sellers, they don't care...
But yea it makes sense, internal ISA cars are gone and lost forever, only the external breakout box remains...
I have 2 MPU401 ISA cards and a first generation MT-32 stashed away at my parents home in Austria. But I am in the process of getting some gear over here to Australia.
Also regarding cost...
When I was a kid during my summer holidays between primary and secondary school I did some work on a building site for 4 weeks. I got just enough money to buy a Sound Blaster (mono 1.5 version I believe)...
Wheras today you can buy pretty much any sound card you want for a fraction of that. MT-32 and LAPC-I cards cost a small fortune when they where in their prime. So the price isn't that important to me, they are still very cheap considering and will only keep going up in price as time goes on...
I bought 2 Creative Soundblaster Pro 2.0 on ebay for 20$ each. Now some think that's expensive, but 40 bucks is not a lot of money for the fun I will have playing with them..
A few tips regarding saving money are to buy in bulk to save shipping. E.g. look if a seller has other things that might interest you. From the US the items are often cheap, but the shipping is expensive. So just buy a lot of product and that will lower your average price.
The really cheap purchases are boxes of hardware. E.g. I got a box with a few boars, ram, cpus, video cards for 30 bucks. It works out to mabe 1 or 2 bucks per item which is very cheap...
And when you buy bulk you can always sell some of the other things and maybe even break even 😁