Actually, it would make economic sense for them in that their own assembly halls have already been paid for (many times over!), so holding district – I mean, regional – conventions in them would not include the significant overhead in the rental of large community venues such as sports arenas. And, don’t forget, their own lands have religious tax-exempt status!
So, it seems that money just coming in rather than having to go out would be a great deal, indeed, for them.
Although, there seem to be a lot of international – I mean special – conventions taking place in the very recent years. I guess these “special” occasions are an extra incentive for donations, including foreign as well as domestic.