There have been some interesting and well placed truth's spoken here (Webb, Stephen, Bill, Paul, etc..)! That being said, there is a point where I see this teetering on the verge of the old pennywise/dollar foolish thing. If you want the airplane to do a certain thing (in this case IFR work), then it really should have the appropriate equipment. Trying to do something like create an IFR bird at VFR prices at the absolute bare bottom works sometimes/kind/sorta, but most of the time ends up as folly down the road from a good reliable, safe, and functional standpoint. In this case, the 300XL is OK but certainly not a great use of $$'s given where the world is going for IFR. Everybody starts out with a certain budget or bucket they have to build the airplane by. It's how you ration out that bucket of money to make the best use of each of those $$'s that really, really matters.
I guess I'd say the same thing I tell many of my friends and customers. If you want to make it IFR, then do it...don't try to make it "almost" because I can guarantee you 100% you'll kick yourself later. I'm not an advocate of wasting money, just doing things right. If you truly can't afford to make the plane how you will want it to perform, then do the best you can. It's just most all of the time people look back and wish they'd have done what they wanted to do with the plane....even if it cost a few extra pennies. I don't think I've ever heard people come back after the plane is flying and tell me "boy I'm upset that I purchased the better equipment", but I almost weekly hear "jeez I wish I would have just bought that thing to begin with...will you take my other stuff back in on trade and sell me that other unit"?!?!
Sometimes people don't know the questions to ask, hence all the good advice I've seen on these forums. And also, don't be afraid that we'll look down on a Bearhawk builder....lots of RV guys are building Bearhawks, and lots of us have our eyes on that plane!
My 2 cents again!
Cheers,
Stein.
PS, I'm glad to see that most are over that ludicrous and dubious notion I've seen as of late that handheld GPSes are ok for IFR work!