Why doesn't he like tubes? Without them you need a "macro" lens which will cost more and I'm not sure they'll reach 1:1 without tubes. You can mount the tube and leave it on if this is a macro only setup.

Pentax 645, a long enough lens plus a tube or two. I think that would fit below your budget. TTL metering plus TTL flash if you want to add the Metz module. If he could live with manual aperture he could get the Kiev 60 tubes and lenses but I don't think with todays prices this will save any money.

If you want built in metering I think the Pentax 645 is the lowest cost option. For comparison the Bronica ETRSI metering prism often costs more then the complete Pentax 645 body,insert and normal lens.