Forget about high-sec exploration! Data and relic sites are worth nothing and DED 1-4/10 sites are a perfect example of "rat race". Train interceptor and try low & null sec!

However keep in mind pure exploration (running data & relic sites) is not very profitable even in null-sec. While you can occasionally find very expensive stuff on average you earn less ISK than during level 4 missions running. On the other hand combat exploration in low and null sec can be very lucrative because one DED site can drop module worth several hundred millions ISK! Well, combat exploration is harder because you have to train T3 strategic cruiser and you have to invest several hundred millions ISK to purchase it.

Relic Ceptors? Care to show a fit?

Yes! As I said before interceptor is very good choice if you want to explore in null-sec using gates to travel. Of course you should train Archeology to IV or V and maybe invest in Sisters Core Scanner Probe to gain more sensor strength but it would add 37 mil. ISK to your initial investment cost in this activity. Notice the best side of interceptor is large degree of safety in null-sec. I think much higher than cov-ops T2 exploration frigate (training time is exactly the same!).

My second attempt to enter null-sec was successful! After jumping through two wormhole systems I entered null-sec in Providence region and quickly returned back to safety. However it took me an hour to scan down signatures because wormhole systems usually have plenty of them (even over ten!)...that's a downside but in fact I did not meet any hostile action during five hours I spent in wormholes today in my Astero.

Of course traveling to null-sec via wormholes you cannot know where you eventually land. For pure exploration purposes that's not troublesome because exploration frigates can run data/relic sites everywhere in null-sec using the same fit. However combat exploration is much more "unfriendly" because without knowledge what rats you will be fighting it's really hard to fit T3 strategic cruiser and load proper missiles.

I had stated here - https://pilgriminexile.wordpress.com/2014/02/10/how-much-probe-scan-strength-do-i-need-for-exploration/ - and then I calculated probe scan strength for all bands.

I did it to figure out if Emergent Locus Analyzer subsystem is required to find all DED and Unrated plexes flying Tengu. So without it I could find them all except DED 1/10.