Hi J & K
If you're looking to celebrate a special occasion during your New Hampshire stay, I'd suggest The Bedford Village Inn, however, inexpensive is not a word that comes to mind for this place (avg. prices start at $250/night). Quite a bit less $$ is the Fox Brook Farm in nearby Amherst (
Rooms & Rates at Fox Brook Farm Bed & Breakfast, Amherst, New Hampshire) very convenient to both Bedford area and Nashua as well.
If you decide that a B&B isn't in the budget for your weekend here, there are several alternatives. Super convenient to the airport in Manchester is the Highlander Inn (
The Highlander Inn - Manchester, NH Lodging).
If you're going to be scoping out the Exeter area as well as Manchester/Nashua and surrounding towns, I would recommend staying in the Manchester area instead of Nashua. It's only 10 +/- miles away, but Manch. is more central to where you seem to want to be. Convenient to the interstate as well as east/west highway 101 for access to Exeter and the seacoast.
Looking forward to seeing other responses!