Initially, all three Hirth engines were offered; builders could keep the 40 hp engine, or "trade up" to 55 hp or . The latter, which Bede had developed with Hirth, was now considered the baseline engine for the aircraft; when equipped with the original 40 hp the aircraft proved to be underpowered. In a late 1973 newsletter to prospective owners, Bede suggested the 70 hp model and discouraged use of the smaller engines. Prices had risen throughout the 30 months since deposits were first taken. Originally priced at $1,799, the base price was raised to $2,599 with the 55 hp Hirth, and owners were offered a "trade up" for the difference in price if they had ordered the aircraft with the original 40 hp engine.