From Wayne Sayles' vcoins.com store:
http://www.vcoins.com/ancient/sayles/store/dynamicIndex.asp

 
Alexandria, Egypt: Maximinus I / AE tetradrachm

AD 235-238. Year 4 (AD 237-238). Laureate bust of emperor 
right / Bust of Nilus right. VF with rough surfaces. Emmett 
3292(4). Scarce.

 Price 
US$ 110  euro 93.83 £ 64.13

 Rates for 11/25/2005