Monarch are Expensive from wat ive seen, even the ZB operation
Something I will second. From my experience, Jet2 have far more reasonable fares, particularly in peak season, when compared to the 'special' Monarch offering. Although the aircraft on ZB/MON are in slightly better condition, their complaisance and high fares in the saturated market where they operate scheduled services do not attract me at all. This is opposed to Jet2's innovative (IMO) approach (varying destinations, 23kg checked baggage allowance e.t.c)
As a regular on the BLK/LPL/MAN -TFS, I rarely choose Monarch because of their high fares over the busy periods. Often I have even gone on EZY and FR, both of them much cheaper although the latter of the two in particular offering some very low fares when compared to ZB or even, LS.
This is the reason why I think that LS should try to go for markets that EZY and FR provide fewer (although EZY tend to reach these places now) or no services on. Croatia, Tunisia, Turkey, Bulgaria, Cyprus, under served Greek Islands (e.g Kos/Kefalonia), or even Cape Verde, The Gambia or Florida with 767s. A mix of established and up and coming holiday destinations which can be well supported with low frequencies and charter capacity should be the direction LS should head in. I'm sure the charter companies could do with the extra capacity to such places at certain times (e.g TCX have been using MON a lot).