I would think that these boats would be priced 'fairly' at $500.00 RTR but not $1K. Just looking at the rudder on that boat it looks like it's going to break, easily. I am sure you could easily build a GOOD boat yourself in the $1K range and that would use top shelf parts, a billet stinger drive and billet rudder setup and other top quality parts.
The hull, motor and radio system seem to be the most expensive items. I guess the thing that perplexes me the most about these 'Proboat' models is that they are not 'cheaply priced' but seem to be poorly contructed compared to what building your own $1000.00 boat would get you.