Hi Janie
You need to realize 1st off you're buying top of the line & it may be hard to recoup the cost if you ever decide to sell. The metal roofs you're talking about are very good & last as long as you'll ever want but again you could but yourself a slate roof, a Spanish Tile roof, Cedar Shake roof complete with underlayment if you wanted. If you already have roof decking as oposed to just strapping there are very good, cheaper roofs you could have installed. A few things about metal roofs to consider; they need to have very good insulation under them & need to be properly vented. Insulation because there's alot of air flow going out through a metal roof & you don't want the heat going with it. You also need to have a vented air space in the attic/ceiling, to prevent ice build up in the winter (ice dams), which I don't know if that's a problem in your area. these 2 have to be dead on because you don't want to create a condensation problem, so balance is needed here more than you'd find in other type roofs. Lastly metal roofs don't do well beneath large overhanging trees. Actually none do but the meatl roof will cost a hell of a lot more to repaire the damage. It's not like pulling a couple pieces of slate or replacing a few shingles, you got go pulling inter-connected sheets of metal the length of the roof for one dent or slice unless you want to just patch it which is sightly if it's just a dent.
The wood replacement, is it decking or roof joists, either way once the old roof is off either job should be easy & cheap. If you have existing decking (deck replacement per sheet of 4x8x5/8 or 3/4 should be no more than $60 each, all material & labor included) by the way decking shopuld be no thinner than 5/8" thich 3/4" is better but more costly.
You can get a good shingle roof (roof slope should be better than 1/4" per 12' slope) with any where from 25yr (20yr not recommended) to a 50 yr roof for half of what gets you a metal roof. Repairs are also very cheap.
If you have a low slope roof (under 1/4" per 12" then you may want to consider a PVC or Rubber Membrane roof.
Tell me mor about what you're looking for & what you now have & what kind of wood repair/replacement's needed & I'll give you more options. $27,000 is way out for what you probably need or want. 1800 square ft bunglow (bunglow's are usually considered neither low nor steep roofs generally a 5 or 6 pitch which means that the sq. footage of your roof depending if you've got valleys, hip, domars, shed or gables, somewhere around 22 sqs or 2200 sq ft (guessing). It's been awhile & I'm not familar with your area of the country but for under $10,000 & that's high you could have yourself a very good roof with all the extras, that includes removal & disposal of all the old, renailing the decking, ice & water shield, soffit vents & ridge vents, all new flashings, hurricane nailing (6 nails per shingle instead of 4, & watch out for gun nailing rather than hand, some people are sloppy when it comes to using guns & some cheat nail or what's called "skip nailing" they don't flip the end bach to nail off the end of a shaingle when they are coming up on the next row). Anyway this is probably a bit more than what you need or want at the moment so let me know your thoughts & we'll get you all cover up for a better price than what some one's trying to sell you. That's a roof for Beverly Hills.

Barry