Case: Sale of EVA-covers

About the project:
Production of car roofs from EVA material
The Task:
Increase the volume of cold traffic at the price of 5$ cheap, so that with current conversion indicators from the request to the sale, the price for the shipment of the goods was up to 9$
Problems that I have faced:
When scaled through the inside of one advertising cabin increased the price per application / sale
When launching from other advertising accounts were blocked
How to solve the problem:
Other websites were scaled.
Advertising on large volumes on different websites
On the sites set different prices, thus made retarget and those people who didn't buy from the first site.
Used by websites:
HTTPS://eva-trade.in.ua/
https://evatrade.com.ua/
HTTP://eva-lux.in.ua

The Results:
Advertising budget: $61,732,92
Number of Applications: 15 094
Number of purchases: 7 547
The average price of the application: 4,09$
Average purchase price: $8.8
Average check: 1200 UAH ≈ 44,4$
Revenue: 335 086,8$
ROAS: 542.8 %