Not really. Materials and manufacturing costs for perovskite probably already beat silicon if anyone scaled up. It's efficiency and durability we're waiting on.

If you look at pricing a large solar farm you'll be surprised that the cost of modules is probably only a third of the total cost but when you reflect on land, cabling, inverters, grid connection, and installation then it's not really surprising. Given these costs, you've got an obvious incentive to buy higher efficiency modules for a small premium for savings on installation, mounting, and land use and a disincentive to buy cheap and not yet high efficiency perovskites.

This is why companies like OxfordPV are targeting tandem perovskite-silicon cells with efficiencies at 30%. Even if this costs 1.5 times as much as a 20% efficient silicon cell, it'd still bring down the price of your solar farm.

They both matter, but cost is king, and is a function of lots of things including efficiency.

The cost for obtaining 1 kWh from a 90% efficient panel that lasts 1 year will be much greater than the /kWh cost of a 40% panel that lasts 10 years.

Yes. Cost-per-watt is king.

And solar panels are already very cheap.

(The only exceptions are space/weight constrained applications like satellites.)