Rated power: 300W, Package Size: 20*11*4.9cm (7.8×4.3x 1.9 inch), Weight: 0.8 kg, Output frequency is: 50Hz for 220V model /60Hz for 110V model., Peaks Power: 4000W, Output voltage: AC 110V /220V for your choice, Output waveform: Modified sine wave..
Go down and check coupons out. Remember to check price history if it is available. Do you want to know what the best price is?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I am tired of searching coupons, but I found one for you…
Link: Banggood product page
1. ($44.99): Cuponation9
just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): hoNEYbGdeAlS, BG6d2f05
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for 3000W 12V to 110/220V AC Inverter. The lowest price was: $28.99.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).