You know what, I'll give you a cut rate deal on that.
Pay me 25% of the estimated price of $22,300 (a total of $5575) and I'll make this app for you.
That quoted price is absurd. Parsing the forum's HTML code into lists and elements is not difficult and this app would require extremely insignificant amounts of original content. A good programmer could do this in three hours, that would come out to a rate of approximately $7500 an hour.