Getting to Budapest's Memento (Statue) Park is now very easy on public transportation, which saves money.
Take the newly opened M4 subway (green line) to its end at Kelenfold Pu. The station exit leads to a street level bus stop loop and parking lot. Take bus #101 to the park (about a 10 minute ride). Memento Park is a fixed stop on the route and you can't miss it. Don't take the #150 bus - it weaves through several neighborhoods and makes way too many stops. Please consider this revision in your next issue of your excellent travel guidebook for Budapest.
Just visited the park on June 17 and enjoyed it.
Happy travels!