Well if you're an S/FO and you join BALPA it is half price for your first year and 0.75% for your second. You'll get tax relief on your subs to the tune of 40% of 66.67 % of your membership fees.
Rough figures suggest it maybe £2 more expensive per month than the IPA for the first year.....How does £13.00 a month sound? It maybe less as those figures are calculated on top scale old SFO....
Anyhow you could give it a go for a year and see what you think.
You can join at
www.balpa.org