FlyerTalk Evangelist
Join Date: Aug 2011
Location: Barcelona, London, on a plane
Programs: BA Silver, TK E+, AA PP, Hyatt Globalist, Marriott LT Plat, Hilton Diamond
Posts: 13,033
30k is Economy "Promotional award ticket" - i.e. saver award space.
45k is Economy "Award ticket" - i.e. last seat on the plane space.
If you have enough miles and there are enough seats available, you should be able to book 3 "award tickets" for 3 x 45k miles.