Tomato Seeds - The cost per seed !

An appointment for a scan on my shoulder and rain stopped play with regards the allotment. But in the morning I completed the spread sheet on my Tomato plants. £41.63 worth of Tomato plants cost me £7.50 in the Wyevale sale as the Harbinger were free when you bought two packs of T&M seeds. so that's a saving of £34.13 just on tomatoes.
 
What I can't believe is the difference in the RRP vs quantity of seeds. 

Having the spread sheet I have worked out the cost per seed for all the different varieties I bought based on the RRP. The most expensive is the Heartbreaker at 49.8p so nearly 50p per seed and the cheapest is Moneymaker at under 3pence per seed 2.7p That's a 47p difference how on earth do they justify the difference in price? 

 

After the scan at the hospital, I went to Wyevale to have a look around and as the potatoes looked better than the BQ Potatoes at 3 bags for a £10 I have bought the last couple of years, I paid the extra and purchased

Gardeners Treasure Kestrel Second Early Scottish Basic Seed Potato £4.99 / 2kg
Gardeners Treasure Desire Maincrop Scottish Basic Seed Potato £4.99 / 2kg
Gardeners Treasure Cara  Maincrop Scottish Basic Seed Potato £4.99 / 2kg

I have the Early Swift 8 seed potatoes for a £1 from the £1 Shop so unless I see some other type of Early in Wilko or the 99p or £1 Shop that may be it on the potatoes. I need to find a couple of trays and put them out for chitting in the greenhouse, but they will come in when threat of Frost.