As designed, you might want to create a new estimate. That way your original estimate reflects the prices in effect at the time that estimate was generated.
To update the unit prices for one estimate, a group of estimates or all estimates, you would need to pull up the Estimate Data records for that estimate or estimates, put the cursor in the item field and use the Relookup option in Records to relookup the unit prices. This is a process that could be scripted.
You could also change the design of your database by changing the unit price field in Estimate Data into a calculation field that copies the price from Products instead of looking it up. A field of type calculation would then update automatically with each price change.
Thank you PhilModjunk.
that helps a lot. is changing the unit price field the way you described it a easy change?
"easy" depends on your level of experience/knowledge. It should be very simple to do, but any time you make a significant design change, make a backup copy of your file first so that you can start over again if the change doesn't function as expected or you change your mind about making the change.