How can I check if a transaction is mined into the blockchain ? How much time does it take for this if the transaction is less then 1000$ ?
You can paste the txid in a block explorer, or just look at the history in the gui to see if it has started confirming.
In cli I think
show_transfer <txid> should do.
No matter the amount, if the network is not overloaded, your transaction should be mined within an average 3 minutes (1 minute average for current block to be mined and then the 2 minutes blocktime for the block including your transaction to be mined).
print_tx monerod command finds a transaction by its txid:
The output will tell you whether that transaction was found, and if it was, whether it is mined or still in the txpool. If it was mined, you'll see when it was mined.
Assuming the transaction is valid, the time it takes to be mined depends on its fee, and how much backlog there is in the txpool. Transactions are included starting with the one that has the highest fee per byte. Typically, multi-block backlogs are rare. Blocks are mined every 2 minutes on average, but variance can be substantial for small number of blocks.
The value of the ouputs has no relevance.
Enter the the transaction hash ("Tx hash") into the search field in https://xmrchain.net/ and check the "Block:" info on the resulting page. If it says "N/A" it's not mined yet. If there is a number there, it indicates which block the transaction has been mined into. In "No of confirmations:" you will see how old (in blocks) that block is.
Depending on the client you use, this info is usually displayed along with other details about your transaction.
Transaction mining time is irrespective of the $-amount. In general, as el00ruobuob answered, you can expect to wait for about 3 minutes. But it can also take 2 hours depending on transaction backlog.
All the above answers are correct but it's worth some clarification.
In the wallet,
show_transfer txid will show details about the transaction including how long before the funds become unlocked.
In the daemon,
print_tx txid will show whether it's found in a block and optionally (with the +hex or +json) the raw transaction itself.
I would prefer
show_transfer simply because it shows how many more blocks need mining before it's deemed complete (unlocked). Otherwise the transaction could appear in an alternative chain and so still need mining into the main chain.