There's been a bit of a loss of interest among the support and the team's performances on the pitch have levelled off too. After winning promotion in their first three seasons, they missed out on the Unibond League Premier Division play offs very narriwly last season and they're currdently 15th in that league. Meanwhile, their average home league gate has gone from over 3,000 in their first season to just over 2,500 the next year to around 2,100 for the next two years to 1,914 so far this season. Their last home game, a midweek fixture admittedly, drew just over 1,500.
I'm surprised they can't stay in the black AND be more competitive on the pitch, though, given what other clubs at that level survive on. The next highest gates in that division last season were at Boston and were about half of FC United's, while the third highest in the division were at Nantwich, and they were less than a third of FC's. Their ticket prices are GBP 7.50, I think, so even if half the gate receipts go to Bury, they should still have a bigger budget than pretty well anyone else in the league.
I think they're looking at the ground be more move as a chance to grow their support, because from what their leaders say, they seem to think that more people within the Greater Manchester catchment area would be willing to travel to a location within Manchester than to Bury. I'm not so sure, personally.