Good point regarding quantity & PAR versus rough sawn. Fortunately I can store 10cu.ft. in my shed, so quantity is not an issue.
I looked at the price difference between PAR & rough-sawn and my investment in a jointer & a thicknesser has already paid off. I buy 1" rough saw ash & plane down to 3/4". Allowing for some waney edge (very little) and a few splits, I get probably 50-60% (conservative) of the volume after dressing & squaring the wood, so buying 240 foot length of 1"x6" (10 cu ft), I get about 200-220 feet of 3/4" x 5" (more like 5 1/2" generally), which would cost £300+ from British Hardwoods as opposed to £200 for the rough sawn timber from my local supplier.
Please don't think I'm knocking British Hardwoods, I've used them before and they're great; I'm just pointing out an alternative that might make sense if you can envision using enough wood to justify the initial investment in tools.
As a matter of interest, my skill at thicknessing & jointing does not (yet) match the evenness of buying PAR timber
, so my belt sander is useful. But I'm getting better.
Obviously from a cost perspective, you might want to factor in the cost & maintenance of a thicknesser & jointer - and also perhaps the extra time involved in preparing the boards, but to me, this is all part of the fun of making huge quantities of sawdust
Just my €0.02