For economically priced lodgings, avoid the lodges and try the following:
West Glacier: West Glacier motel
Many Glacier: Swiftcurrent Motor Inn and Cabins
St Mary and nearby: Rising Sun motel and cabins; Johnson's cabins (furnished, lots of August availability:
https://www.webreserv.com/book.do?busin ... tid:0=2836); could also look on vrbo, as there are many private cabins
East Glacier: Whistling Swan Motel (
http://www.seeglacier.com/whistling-swan-motel), and a largish motel next to it whose name I can't pull up. Several motels that look dicey and provide inconsistent service.
Rte 2 near Izaak Walton Inn has several OK motels and cabins, including cabins owned by the Inn.
None of this is luxury lodging! You may have to walk to a central restroom facility.
If you want to stay at Sperry Chalet or Granite Park Chalet, it's best to try to get one room for 4 because so few rooms. There are various activities and hikes that might make 2 nights more reasonable than one.
OTOH, if you want resorts, go for the lodges. Again, look outside the Park boundaries. Glacier Guides has a lodge in West Glacier, e.g., with availability in August (
https://glacierguides.com/reservations/ ... s-lodge-ro). Xanterra has only a small bit of the lodging.