Windjammer Technologies Ltd has been having difficulty collecting its accounts receivable. For the year 2019, the company increased the allowance for doubtful accounts by $53 000, bringing the balance to $74 000. At the end of 2019, accounts receivable equalled $425 000. When the year-end audit was being done, it was decided to provide a further $45 000 of accounts receivable that were doubtful, and write off $30 000 of accounts receivable previously deemed doubtful. 

Calculate the following: 

1. Bad debts expense for 2019 

2. Allowance for doubtful debts at the end of 2019 

3. Estimated collectable value of accounts receivable at the end of 2019.