Saint Athanasius Academy Septuagint is an LXX translation found in the Orthodox Study Bible published in English in 2008.
The LXX transition is in modern English and the cost of the Bible is relatively low.
http://www.barnesand..._-2672035177385
If you like quoting out of Brenton, CAB (Complete Apostle's Bible, or the ABP (Apostolic Bible Polyglot), then this one should be looked at as well.
I discovered by randomly purchasing this study Bible for reference a couple of years ago. It is worth the notes and the translation of the Psalms alone!
I also like the the various inserts that explain Orthodox doctrine such as a good explanation of "partaking of the divine nature" from 2 Peter 1:4.