Is it better to use oranges that are under-ripe or over-ripe to make marmalade

Costs to consider when making jam:

One-Time Costs

• Pressure canner
• Water-bath canner
• Large pot for making jam in
• Strainer (can use a colander-type item or something like a Squeez-o)
• Jar rack that goes inside the canner
• Jar lifter
• Funnel
• Jars
• Freezer-safe containers
• Jar rings

Recurring Costs

• Jar lids
• Fruit (you can often get pretty cheap fruit in bulk from an orchard)
• Pectin
• Sugar
• Spices
• Energy usage (stove)

Compare costs for freezer jam (no canner required), pressure-canned jam (pressure canners are expensive), and water-bath canned jam. Also compare for recipes that do vs do not contain pectin.

If you can get a lot of the one-time cost items free (from grandma's attic, most likely), and if you can get the recurring cost items on sale (or from your own garden), then you can probably come close to commercially priced jam.

Personally, here's what I look at:
A) The cost of the item I would normally buy at the store - generic, cheap brand. Let's call that price X.
B) The cost of the item I wish I could buy at the store - the really good stuff. That price is usually about 2x to 3x.
Then, my goal is to be cheaper than 2x.

Another Cost Consideration If you give homemade jam as holiday gifts, spending less than you otherwise would on a gift, there's additional savings for you.

Have you tried using a candy thermometer and testing the jam when it's at 220°F?

An alternative to the method that you use is to use a spoon and do the 'two drop test'. If you dip a cold metal spoon into your jam mix and then lift it. When the mixture is only just boiling it will drip off and be light. As the mixture continues to heat the drops that fall from the spoon will be heavier When the two drops form and fall off the spoon it should be ready. I'll be honest though I much prefer the method you use and this is just an alternative.