Are you a millionnaire? Copper pots would be £££!
Slugs will sometimes eat spring bulbs - but it's rare. You can buy copper tape that you put around the top of ordinary flower pots and it stops them being able to get up to the plants (obviously this doesn't work if they can just climb up a neighbouring plant and bypass the tape). The cheapest place for this - if they still have it in - is Aldi. But I wouldn't worry too much if it's bulbs. Hostas on the other hand....
In outdoor containers, I normally plant spring bulbs in the cheapest of the cheap compost. I shove in a bit of grit or perlite (I think the latter might work a bit better), which you can buy separately for around a fiver a bag. Lots of people use broken flower pots in the bottom to improve drainage, but if you're doing a bulb lasagne then it can get in the way a bit.
One exception would be if I am planting something choice, expensive and rare that costs several quid a bulb - then I'll probably go for bulb compost. another would be for growing bulbs indoors, where bulb fibre tends to smell a lot nicer - it really is worth paying the extra for this.
But for your bog standard crocuses, daffs etc in a pot outdoors, cheapo stuff seems to work fine. I give em a feed when they're over and let them die back, then plant into the garden for the second year.
The thing about bulbs is that they are exquisitely designed energy stores. The base has so much stuff packed into it that you can get away with not providing the richest and most costly earth for them to sit in.