It used to be that I would double-click on a cell to edit it (as I do now) and the value was highlighted, so I could immediately start typing over the value already there. Now the cursor is put at the front of the number, so I end up using Ctrl-A to highlight the text before I start typing in a number to replace it (or at least I expect I will be doing that the majority of the time, or going with the slower option of holding Delete or something to get rid of it). Maybe I'm in the minority in wanting to overwrite the current price most of the time.
As for number alignment, I think it would be nice if the tens columns, hundreds, and so on were lined up. If everything had the same number of digits it wouldn't matter, but going from 7 to 6 to 5 digits with left-alignment looks weird to me.