Yep I can say from experience the MP is the way to go if your looking for a good HP mold. The one cavity Lyman can and will produce some nice HP's but like was mentioned you have to keep that pin hot and run your alloy right at the 700 degree area as well to keep everything up to temp. Throw in that once you start it is non stop pour, pull, reinsert, and pour again about as fast as you can get away with to keep it there. With the MP's you have WAY more flexibility and the pour rate is 4-1 over the Lyman.
But if you could also look over at Hollow Point Bullet Mold Service
to see if he might have a double cavity one that suits your fancy as well. Or he can convert one to the Cramer style for cheaper than the MP's.
That said, I have picked up a couple of the after group buy left overs and they usually run about $130 depending on how you set them up pin wise. Even a couple with all pin options were within that range. I do however have to warn you, once you get one, others WILL follow. Sorry but it IS the truth.....
For some awesome expansion try and pick an alloy somewhere in the 20/1 or one with 2/2/96 ratio tin/antimony/lead or slightly less. Right now I am working on one that is just a touch harder than the 1.5/1.5/97 I used for these,
That alloy is fine for the 1000fps range I am using from my 45 Colt, but for the faster 41, and 44 mags I need just a touch more hardness to keep them together in similar fashion.
Hope this helps,
BTW if you can find one of those thin foam work out mats, it will help out quite a bit on top of that new bed you spoke of.....