I've been instructing for well over 1000 hours without any IMC or IR. If you fly from an airfield without an instrument approach, you'll still be grounded on the non VMC days anyway.
In terms of cost of the FI test, there's a lot of stuff on the ground. The actual flight is probably shorter than an initial PPL test as there's no navigation section, about an hour and a half as I remember. Just be prepared to spend all day being grilled indepth and handing over a large amount of cash to the examiner.