I have attached copies of both Proposals. There are multiple reasons for the price difference that I have outlined below. However, I will note that the most recent proposal (15197-01) actually has the lower price (you mention below that it is higher).
Proposal 15061-03 is for an air by pass tray for shop #QA-0076 while proposal 15197-01 is for shop #5783. As well, the sifters use different screens. Proposal 15061-03 is for 2000 micron screen while proposal 15197-01 is for 425 micron screen.
Unfortunately, proposal 15061-03 is no longer valid due to our 90 day validity period for proposals. We will still honor the price of 15197-01 thru 16.October.2015. As of 19.August.2015, we have had approximately a 3% price increase on all items. You will notice this price increase on future orders.
However, before placing an order, I would verify which shop # you are requiring the replacement air by pass tray for as well as the screen aperture (micron) requirements. Unfortunately, all screen tray orders are non-returnable.
Depending on the quantities purchased, we may need to add export crating expenses.
Please let me know if there is anything else that we can do for you.