This is most likely because you happened to use price per unit, and at the same time specified a price per kg but entered weight in grams. This means the calculation will be 1000x too high. Please correct your weight or price such that they match.

First of all, you need to turn on price crowdsourcing under settings (only done once).

Tap the shopping list item in question, e.g. apples.

Enter the price per item in the price field, then select the amout of items you plan to buy at the top just under the image by tapping the plus or minus buttons.

If you go back to your list, you can see that the line reflects the price (per item) and that the total price row at the bottom now reflects the amount x price.

First of all, you need to turn on price crowdsourcing under settings (only done once).

Tap the shopping list item in question, e.g. apples.

Then tap the name field to expand additional detail fields and enter the weight and unit you are buying.

Set the unit to the unit that the price is given for, e.g. if price is per kg then enter how many kg you buy.

A toggle will appear just above the note field that lets you toggle ON price per unit.

If you go back to your list, you can see that the line reflects the price (per unit) and that the total price row at the bottom of the list now reflects the amount x weight x price

No, your premium subscription is pre-paid and non-refundable.  In general Grosh is try-before-you-buy with the vast majority of features being available in the free version, see also this premium app overview. The primary motivation for purchasing premium should be that you want to support the continued development of the app, and secondarily to get a handful of extra features. If you want to retract your support to us or for some other reason request a refund, then you should not contact us directly. We cannot refund as you actually bought the premium subscription from Apple or Google, see this FAQ entry.

If you’re logged into the app, choose Logout under Settings. On the login screen, press “Forgotten password”, enter your email and we will send you an e-mail with a link to reset your password. Through this link, you can choose a new password. Use that password to login from the various devices where you installed Grosh.