Long mortgages are a really really bad idea with high interest percentages. Unless you've locked in a low percentage from before corona you're going to pay almost as much in interest as you'd be paying for the house...

To pay off 300k within 30 years at current mortgage interest of 4% you'll have to pay 1432/month (215k of interest will be necessary)

Depending on the amount of taxes you have to pay, thats likely > 50% of netto wage