Here is my sample of data. Method: I rolled each cooking until 3 chili appeared every time. Recorded each cooking attempts as if I had spent 30 gems to take the best result. This is 34 attempts that I recorded after I had all the ingredients (25 ingredients, 5 chili)
270,1225,350,5840,1225,2565,1385,8010,1625,345, 1605,510,250,1525,1525,70,965,80,100,1225 1125,985,365,2640,60,85,370,290,285,750 90,1385,4560,450, Total 37650 Avg 1107
Keep in mind the average is going to actually be lower because in some of these results the third chili will have completed a position bonus at 5, 10, 15, 20 locations. My overall results ended with around 2500 gems used to get one 1 camp item.
On an unrelated note. I just realized the rollover today deleted last year's Spring event I was working on (with days remaining on timer). I would rather not spend the time and effort to send in another ticket to try and fix the issue. So it looks like this is the end of the road for my time with Diggy. Level 572 (7 year free to play account)