Crimpers are just too expensive.

I know, but I still lust after those Hydraulic Thomas&Betts crimpers
:-). Circa $1000 for the crimper and a single set of dies.

Is there some way to get acceptable crimps
without a crimper.

Not really. But check the local tool rental places and you may find
both the crimper and dies available for a reasonable daily cost.

You can likely rearrange your design such that you don't need a crimper
and instead use Cadwelds.

Tim.