Total Harmonic Distortion: <5%, Power: 3000W, Maximum power efficiency: >86%, Output voltage range: AC 110/220±5%, Overload and short circuit protection: Yes, Input voltage: DC 12v / DC24v, , Low voltage cut-off level: 9.6+/-0.5v, Is there a display screen: No, Output frequency range: 50/60+/-3Hz, , USB output: DC 5V (2.1A), Built-in cooling fan: Yes, No load current consumption: >0.3A, Input DC voltage range: DC12v~DC24v, High voltage cut-off level: 16.8+/-0.5v, Low voltage alarm level: 10.5+/-0.5v, Output waveform: Modified sine wave, Maximum external temperature: <75°C. Basically copy coupon, view price history or create e-mail price alert. Let’s see what best price is ATM.
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 and price update (UTC):
Banggood
Banggood warehouse is located in China. I can’t find any active coupons for this product in Banggood.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG589b2e, BGET10, BG8FORMULAMX, BG424324, BGe245a9
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Price history (for all/most countries) for 3000W Power Inverter DC 12V/24V To AC 110V/220V is here. The lowest price was: $29.99.
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)).