I don't think it's fair to say that either sport or bouldering development requires more or less work and expense.
Nah, this doesn't hold water. Developing is hard and time consuming work. Developing sport routes is always going to be, on average, more work than boulders. Yes there are plenty of routes where the crag is easy access and you can walk to the top drop a rope, and the rock's immaculate, and vertical or less than, and the bolts go in quickly because you can access the rock not be swinging 6 feet away from the rock, and the moves are obvious. But this is maybe 1% of the time. And yeah there are boulders miles from anywhere which are massive and have to have huge cleaning efforts and elaborate patios, but again in a minority.
To illustrate why routes are harder to develop than boulders you only need to look at why boulders traverses are easier to work the moves on than sport routes. The difference in effort and logistics of working out moves, which dictates where bolts need to go, should be obvious.
And something you can pop a ladder against or drop a 5m bit of rope down is in a completely different league of workload/time to a 20m long and overhanging new route - which just to access the face to touch the holds, let alone get purchase to create opposing force to be able to drill bolts into rock - requires you to aid bolt/aid on gear your way up or down the cliff. Then you have to work the moves on a rope and realise you've misplaced the bolts for clipping onsight. Total ballache but strangely addictive.
Showing a lack of experience of developing routes there sorry Liam.